Some types of molten material granulators include a rotary atomiser. In this type of granulator, molten material is placed in contact with a rotary dish and is then projected radially away from the centre of the rotary atomiser by centrifugal force. Ideally, the projected droplets of molten material sufficiently solidify and cool in the time after being projected from the rotary atomiser and before being collected for further use. Various granulator and rotary atomiser designs currently exist.
Some disadvantages of these current designs are (i) their large dimensions, the granulator often needing to be up to 10 m in radius to allow sufficient solidification of the molten material droplets projected from the rotary atomiser, (ii) the costly inefficient use of large airflows to assist in the cooling of the molten material droplets projected from the rotary atomiser, (iii) the generation of ‘slag wool’ in molten slag granulators that causes costly clean-up requirements and decreases operating efficiency of the granulator; slag wool being fibre-like solidified slag that forms from non-ideal rotary atomiser design, and (iv) the residual heat remaining in the projected droplets during the collection stage causing them to stick to surfaces, agglomerate and/or remelt.